The James Norris Memorial Trophy is awarded annually to the National Hockey League's top "defense player who demonstrates throughout the season the greatest all-round ability in the position". The James Norris Memorial Trophy has been awarded 55 times to 23 different players since its beginnings in 1954. At the end of each season, members of the Professional Hockey Writers' Association vote to determine the player who was the best defenseman during the regular season.

The trophy is named in honour of James E. Norris, owner of the National Hockey League's Detroit Red Wings from 1932 to 1952. The trophy was first awarded at the conclusion of the 1953–54 NHL season.

Bobby Orr of the Boston Bruins won the award for a record eight consecutive seasons (1968–75). Doug Harvey and Nicklas Lidstrom have won the award seven times, while Ray Bourque won it five times. The Boston Bruins have had the most Norris Trophies winners with 14; the Montreal Canadiens have had the second most with 11.

Only two players have won both the Norris and Hart Memorial Trophy for the league Most Valuable Player in the same season: Bobby Orr, who won both trophies in the 1969–70, 1970–71 and 1971–72 seasons, and Chris Pronger, who won the Hart and Norris in the 1999–2000 NHL season.